Rotary volumetric feeding apparatus

ABSTRACT

In rotary volumetric feeding apparatus, including a housing having openings for receiving and discharging material, a rotatable peripherally pocketed drum within the housing for feeding the material between the openings and an evacuation rotor for evacuating the pockets at a point adjacent the discharge opening, improvements are provided for spray cleaning the pockets, adjusting the clearances between the housing and the drum to accommodate materials of varying sizes, force-feeding material to the drum and for continuously maintaining the blades of wire-bladed evacuating rotors in a tightened condition.

United States Patent [111 3,

[72] Inventors EdwardBernnrdWelsaelberg [56] References Cited st n y; UNITED STATES PATENTS z g 3,203,601 8/1965 Carson 222/350 x 8 771 3,302,655 2/1967 Sasakiet a1. 134/152 X 25 5 1970 2,857,939 10/1958 Peclis 222/342 e [45] Patented Dec. 2; 1971 Primary ExaminerRobert B. Reeves [73] Assignee Wyssmont Company, Inc. Asszstant Examiner-Larry H. Mamn Fort Lee N AtlomeyBrumbaugh, Graves, Donohue & Raymond 5 ROTARY M 'nuc FEEDING APPARATUS ABSTRACT: In rotary volumetric feeding apparatus, includ- 6 Claims, 8 Drawingllp. ing a housing havlijrlig openings lfl'or recleiviriig:nd disclrarggrlg matena, a rotata e perip era y poc ete rum wt in e 52} US. Cl "2.522550 22222432212 housing for feeding the material beween the openings and an I 565d [3/00 evacuation rotor for evacuating the pockets at a point ad- [51] Int. Cl 222" jacem the discharge opening improvements are provided for 501 Field olSear-ch spray cleaning the pockets adjusting the clearances between f the housing and the drum to accommodate materials of vary- 139/106 134/80 15/ ing sizes, force-feeding material to the drum and for continuously maintaining the blades of wire-bladed evacuating rotors in a tightened condition.

Patented Dec. 28, 1971 4 Sheets-Sheet 1 nun 20 INVENTORS EDWARD BERNARD WEISSELBERG 6 WILLIAM FREDERICK LAMP BY j M Dana/u their ATTORNEYS.

Patented Dec. 28, 1971 3,630,416

4 Sheets-Sheet Z INVENTORS. EDWARD BERNARD wslsszLasRea WILLIAM FREDERICK LAMP 6'' 0 iheif AT ORNEYS.

Patented Dec. "28, 1971 4 Sheets-Sheet 3 64 VIII/III lI/I/I/ I! INVENTORS. EDWARD BERNARD WEISSELBERG & WILLIAM FREDERICK LAMP BY their ATTORNEYS ROTARY VOLUMETRIC FEEDING APPARATUS This invention relates to rotary feeding devices for discharging measured quantities of material, and particularly relates to feeding devices of this type having a self-cleaning capability.

Rotary feeding devices for feeding measured quantities of material have been widely used in the prior art for some time. Typically, the prior art feeding devices utilize a peripherally pocketed drum to feed material from an intake hopper to a discharge opening disposed on the opposite side of the drum from the intake hopper. It has also been proposed to provide a self-cleaning feature for the drum in the form of a bladed rotor which rotates in synchronism with the drum to enter and evacuate each pocket as it registers with the discharge open- It is often desirable, however, to use a single rotary feeding device to handle materials of varying sizes and consistencies; that is, in one application it may be desirable to handle freeflowing materials of a given particle size and in a different but related application to handle materials which are of a coarser or finer particle size or which have a more tacky consistency. Desirably, a feeding device suitable for use with such diverse materials will not only be reliable in that it will deliver material at a uniform rate, but also will require only occasional cleaning.

When used with materials which tend to adhere to the pockets of the drum, as in the food preparation industry, for example, provision should also be made to assure thorough cleaning of the drum surface. Although the evacuating rotors generally remove the majority of the material from the pockets, ultimately a residue of material accumulates which, after a time, may degrade the quality of the material being handled. This, of course, in undesirable where high quality standards must be met.

Food materials, and other similar materials as well, also tend to accumulate on the rotor blades as they pass through the pockets during the evacuation of the material from the pockets. Rotors using cleaning wires instead of paddle blades to cut the material out of the pockets have been proposed,-but have not been entirely satisfactory for this purpose since the wires are frequently broken or loosened to the extent that they do not follow the profile of the pocket so as to cut out all of the material. Maintenance attention must be given to these wire rotor devices, of course, to insure that the wires are properly tightened at all times.

In other applications, it is often useful to force-feed material to the drum pockets as they pass the material entry opening to avoid only partial filling of the pockets. This problem frequently occurs in the handling of crystals, finely divided powders, pastes, precipitates and caked materials, which tend to bridge the entry opening or to agglomerate along the sides of the opening.

SUMMARY OF THE INVENTION There is provided, in accordance with the present invention, improved rotary feeding apparatus of the kind described which includes a provision for adjusting the clearances between the feeding housing and the rotatable drum whereby materials of varying sizes may be accommodated without clogging of the apparatus or without inaccuracies in the volume of material delivered by the apparatus. Also, a uniform feed rate can be maintained without large chunks of material being passed by the drum. The provision for clearance adjustment includes separate members adjustably mounted in the housing in juxtaposition with the longitudinal edges and the ends of the drum.

Spray cleaning apparatus is provided for cleaning the drum pockets after evacuation of the material by the rotor but prior to the delivery to the pockets of additional material through the entry opening. The spray apparatus includes one or more spray nozzles mounted in the housing so as to direct the cleaning medium against the drum surface in a direction at least partly opposed to the direction of rotation of the drum. Any suitable cleaning medium, such as hot water, may be used in the spray apparatus; however, steam is used to particular advantage where both cleaning and sterilizing of the drum are desired, as in the food preparation industry.

An improved wire-blade evacuating rotor is provided to insure positive evacuation of the materials carried by the drum pockets and includes spring-loaded self-tightening means carried by the rotor for continuously maintaining the wire blades in a tightened condition. Also, provision is made for forcefeeding materials to the entry opening of the rotary feeding apparatus to assure that each pocket of the drum receives a full charge of material each time it passes the entry opening. Force-feeding of the material is accomplished by use of an enclosed material-carrying conduit containing a piston-actuated ram or conveyor for pushing the material to the feeder drum.

THE DRAWINGS For a better understanding of the invention, reference may be made to the following description of an exemplary embodiment, taken in conjunction with the figures of the accompanying drawings, in which:

FIG. I is a plan view of a rotary feeding apparatus embodying the improvements of the present invention;

FIG. 2 is a side elevation view of the rotary feeding apparatus of FIG. I;

FIG. 3 is a plan view of the rotary feeder with parts broken away to show the details of construction;

FIG. 4 is a partial vertical sectional view taken along the line 4-4 of FIG. 3, looking in the direction of the arrows;

FIG. 5 is a partial vertical sectional view taken along the line 5-5 of FIG. 3, looking in the direction of the arrows;

FIG. 6 is a horizontal sectional view taken along the line 6- 6 of FIG. 2, looking in the direction of the arrows;

FIG. 7 is a detail view of an improved wire-blade evacuating rotor according to the present invention; and

FIG. 8 is a partial side elevational view partly in section showing a piston-actuated ram for force-feeding material to another embodiment of the rotary feeder.

THE DESCRIPTION 4 Referring to FIGS. 1 and 2, a representative embodiment of a rotary feeding apparatus includes a housing 10, enclosing a rotary feeding drum l2 and an evacuating rotor I4, a drive motor 16 and a variable speed drive 18. The motor 16 and the variable speed drive 18 are fixedly mounted on frame members 20 and are drivably connected through the sprocket chain 22 and sprocket wheel 24 to the evacuating rotor shaft 26, which is journaled in the housing 10, also fixedly mounted on the frame members 20. At its end opposite the wheel 24, the rotor shaft carries a drive gear 28 which meshes with a driven gear 30 keyed to the drum shaft 32, also journaled in the housing 10, whereby the rotor shaft 26 and the drum shaft 32 rotate in synchronism. Feeding rates are varied to meet the requirements of different processes, or to facilitate the handling of diverse materials, by adjustment of the variable-speed drive 18.

An inlet hopper 34 is mounted on the housing 10 by means of the channel member 36 and defines an inlet opening 37 for material delivered to the housing 10. The material may be fed through the inlet opening 37 by gravity or, as more fully set forth hereinafter, by force-feeding apparatus communicating with the inlet hopper 34.

The drum 12, which in the embodiment shown in the drawings rotates in the counterclockwise direction, is generally cylindrical in configuration and includes a plurality of similar peripheral pockets 38 extending lengthwise of the drum of a predetermined volume for receiving the material from the inlet hopper 34. During each revolution of the drum 12, each pocket 38 is filled with material at a point adjacent the inlet hopper 34 and is emptied by the operation of the evacuating rotor 28 at a point adjacent a discharge opening 40 in the bottom of the housing 10. An inspection door 39 having an observation window 41 (see FIG. 6) provides ready access to the evacuating rotor 28. Suitable carry-off apparatus (not shown), such as an endless conveyor, may be provided to transfer the discharged material to the next process station.

In accordance with one feature of the present invention, structure is provided whereby the clearances between the housing 10 and the drum 12 can be adjusted to accommodate materials of varying particle sizes and consistencies. Thus, side members 42 (see FIG. 3-5) are disposed on either side of the inlet opening 37 in generally parallel relationship with the longitudinal edges 43 (see FIG. 1) of the drum l2 and are adjustably mounted on the housing 10 for movement towards and away from the longitudinal edges 43 by means of the end plates 44 which have elongated slots 46 for receiving bolts 48. It will be understood that the side members 42 can be moved vertically to adjust the clearances between the side members and the longitudinal edges 43 of the drum in correspondence with the particle size of the material being handled.

Each side member 42 has a peripheral extent at least as great as the peripheral length of the individual pockets 38 (see FIG. 4) and is generally conformed throughout its peripheral extent to the circular path traced by the longitudinal edges 43 of the drum 12. Preferably, the upper edges of the side members 42 extend vertically in overlapping relation with the innermost end of the inlet hopper 34 to an extent that an overlap exists when the side members are depressed to the lowest possible position.

Substantially planar end plates 50, having a general T' shape, are disposed between the axial ends 51 of the drum 12 and the adjacent walls of the housing 10 to permit adjustment of the clearances between the drum ends and the housing. Notches 52 are provided in the legs of the end plates 50 adjacent the base of the stem portion so that the end plates may be supported on and slidably positioned between the side members 42 in such a way that the vertically extending upper ends of the side members are received in the notches 52. As best seen in FIG. 4, the stem portion of the end plates 50 extends over half of the diameter of the drum 12 and is provided with a semicircular notch 54 for receiving the shaft 32.

The surfaces of the end plates 50 facing the drum ends 51 are substantially smooth to permit free rotation of the drum l2 and to define with the drum ends a uniform clearance space. The rear faces of the end plates, however, are provided with projecting lugs 56 (see FIGS. 4 and 5) which extend perpendicularly from the rear surface and are adapted to abut against the adjacent wall of the housing to position the facing surface of the end plates in spaced relation to the drum end. It will be understood that by varying the length of the lugs 56, the clearance between the ends 51 of the drum 12 and the adjacent surface of the end plates 50 can be varied. Of course, the individual end plates 50 may be readily removed and inserted so that they may be interchanged with other end plates having lugs 56 of the desired length.

Both the side members 42 and the end members 50, as well as the other parts of the rotary feeding apparatus which contact the material, are preferably formed of carbon steel, stainless steel or aluminum.

By selectively adjusting the clearances between the side members 42 and the longitudinal edges 43 of the drum 12 and between the end plates 50 and the axial ends 51 of the drum 12, materials of varying particle sizes and consistencies may be handled by the rotary feeder without any loss of accuracy in the quantities of the material delivered to the discharge opening 40, or without the passage of large chunks of material through the feeder. Also, by preventing the passage of material between the drum and the walls of the housing 10, clogging of the feeder is avoided and therefore downtime for cleaning purposes is minimized.

According to another feature of the invention, an improved cleaning rotor is provided which is particularly useful when wet crystals, powders, pastes, precipitates and other damp materials, or finely divided powders which tend to cake, are to be fed through the feeding apparatus. Referring to FIG. 7, a preferred embodiment of the improved rotor includes a sleeve 58 fixedly attached to the rotor shaft 26 adjacent one wall of the housing 10 and a length of wire 60 secured at both ends in any suitable fashionto the sleeve 58. Preferably, the wire 60 extends over a pair of guides 62 which are rotatably mounted on the oppositely extending arms 64 of a sleeve 66 slidably carried by the shaft 26 adjacent the other wall of the housing 10. The wire 60 is continuously maintained in a tightened condition by the action of a compression spring 68 which is disposed between the movable sleeve 66 and a sleeve 70 fixedly attached to the rotor shaft 26.

With the wire-blade 60 thus rendered taut at all times, it will follow the contour of the pocket 38 closely and cut out substantially all of the material contained in the pocket. Therefore, the improved wire-blade rotor of the present invention enhances the accuracy of the rotary feeding apparatus by preventing the buildup of residue in the pockets 38 and provides a greater self-cleaning capability than that possessed by prior art rotary feeders. The spring loading of the wire 60 imparts resiliency to the wire which also effectively reduces the frequency of wire breakage during operation, and which eliminates the need for frequent manual tightening of the wire.

Referring to FIGS. 2 and 6, a further novel feature of the present invention includes a plurality of spray nozzles 72 spaced along the axial extent of the drum 12 and connected to a similarly extending fluid conduit 74 which is disposed in the housing 10 at a point between the evacuating rotor 14 and the entry opening 37. Preferably, the spray nozzles 72 are directed toward the surface of the drum so that the spray streams are discharged against the pockets 38 in a direction at least partly opposed to the direction of rotation of the drum (see FIG. 2).

The combined cleaning action of the evacuating rotor 14 and the spray apparatus is particularly effective in cleaning the drum 12 since substantially all of the material in the pockets is removed by the rotor 14 during the evacuation step and the material which does remain is readily removed from the pockets by the effect of the spray stream impinging against the pocket surfaces. No caking problem due to moisture collecting within the pockets exists, therefore, since virtually all of the material is removed from the pockets 38 during each revolution of the drum. Consequently, the feeding of material need not be interrupted in order to clean the drum, but both may be accomplished simultaneously.

Although hot water or other suitable cleaning liquids can be used, steam is preferred inasmuch as the drum surface can be both cleaned and sterilized. The use of steam is particularly advantageous in the food preparation industry where sterilization of the drum surface is especially desirable. Suitable gutters and waste-collection ducts (not shown) may be provided if needed to carry off the waste cleaning fluid and debris.

FIG. 8 shows a further novel feature of the present invention in combination with a modified embodiment of the rotary feeding apparatus, indicated generally at 80, having the standard pocketed drum 82 and a solid-bladed evacuating rotor 84. A ram 86 is mounted for reciprocating movement within a conduit 88 to force-feed material to the drum 82 and is actuated by a double-acting piston 90 operably received in the usual manner in a cylinder 92 having pressure connections 94 and 96 for effecting reciprocation of the ram 86. Additional material is added to the conduit 88 through a hinged closure 98, which is secured in the closed position to the conduit 88 by suitable means such as wingnuts 100. By supplying a continuous pressure through the attachment 96, a continuous forced feed of material to the drum 82 can be accomplished, thereby eliminating the tendency of the material to bridge the entry opening or to form agglomerates along the side of the opening.

The force-feeding apparatus shown in FIG. 7 is advantageously used in conjunction with the novel clearance adjustment structure of the present invention inasmuch as the escape, or seepage, of material between the drum edges 43 and ends 51 and the respective walls of the housing is effectively controlled even under pressure-feeding conditions by proper adjustment of the clearances. Thus, even materials of a fine particle size may be force-fed to the rotary feeding apparatus without any sacrifice in feeding accuracy.

It will be understood by those skilled in the art that the above-described embodiment is intended to be merely exemplary, and it is susceptible of modification and variation without departing from the spirit and scope of the invention. For example, instead of using a single length of wire to form both of the cleaning blades of the evacuating rotor, two separate wires may be used which may be secured separately to the arms of the movable sleeve 66. Also, the end plates 50 need not be generally T-shaped, but rather may be generally rectangular or any other suitable shape. Other mounting structure may be utilized within the housing to position the modified versions of the end plates 50 between the drum and the housing walls.

lt-will likewise be understood that the number and location of the spray nozzles 72 will depend upon the axial length of the drum 12, the size of the pockets 38 and the type of material to be handled by the feeding apparatus, and that any suitable number of nozzles may be used and in any desired location between the discharge opening 40 and the inlet hopper 34. All such variations and modifications, therefore, are included within the scope of the invention as set forth in the appended claims.

We claim:

1. [n a rotary feeding apparatus comprising a housing, a generally cylindrical drum rotatably mounted in the housing and having a plurality of similar peripheral pockets, the housing having entry and exit openings for materials supplied to and discharged from the pockets, an inlet hopper communicating with the entry opening, and an evacuating rotor rotatably mounted in the housing for rotation in synchronism with the drum for entering and evacuating the pockets at a point adjacent the exit opening, the improvement comprising first and second elongated members disposed on opposite sides of the entry opening and extending generally parallel with and in spaced relation to the longitudinal edges of the drum, means for mounting the first and second elongated members on the housing for movement toward and away from the drum to allow adjustment of the clearances between the first and second elongated members and the longitudinal edges of the drum, first and second end members disposed between the axial ends of the drum and the housing adjacent the ends of the entry opening and extending between the first and second elongated members, and means for mounting the first and second end members in spaced relation to the axial ends of the drum to allow adjustment of the clearances between the ends of the drum and the housing, the first and second elongated members and the first and second end members thereby defining with the drum an adjustable clearance boundary between the entry opening and the exit opening whereby materials of varying particle sizes may be accommodated.

2. Apparatus as defined in claim 1 wherein each of the elongated members extends peripherally of the drum to an extent at least as great as the peripheral length of each of the pockets in the drum, and wherein each elongated member generally conforms throughout its peripheral extent to the circular path traced by the longitudinal edges of the drum.

3. Apparatus as defined in claim 2 wherein each end member comprises a generally T-shaped member, the stem of the T being slidably received between the respective drum end and the housing and between the first and second elongated members, and wherein the means for mounting the first and second end members in spaced relation to the drum ends comprises notches formed in the legs of each end member for receiving the first and second elongated members to thereby support the end member on the first and second elongated members and spaced lugs carried by the stem portion of the end member and projecting therefrom a predetermined distance toward the housing, the terminal ends of the lugs being adapted to abut against the inner surface of the housing to position the end member in spaced relation to the axial end of the drum.

4. Apparatus in accordance with claim 1 wherein the im- Frovement further comprises self-ti htening wire-blade means or the evacuating rotor, the wlrelade means includlng at least one length of wire extending axially and transversely of the drum pockets between a first axially-fixed'sleeve carried by the rotor shaft and an axially movable sleeve carried by the rotor shaft, a compression spring disposed between the axially movable sleeve and a second axially fixed sleeve carried by the rotor shaft resiliently urging the axially movable sleeve in a direction away from the first axially-fixed sleeve to thereby maintain the length of wire in a tightened condition.

5. Apparatus as defined in claim 4 wherein the wire-blade means further comprises a pair of guides mounted in opposed relation on the axially movable sleeve and wherein the length of wire extends over the pair of guides and is secured at both ends to the first axially-fixed sleeve.

6. Apparatus as defined in claim 1 wherein the improvement further comprises force-feeding means communicating with the inlet hopper to provide a positive feed of material through the entry opening. 

1. In a rotary feeding apparatus comprising a housing, a generally cylindrical drum rotatably mounted in the housing and having a plurality of similar peripheral pockets, the housing having entry and exit openings for materials supplied to and discharged from the pockets, an inlet hopper communicating with the entry opening, and an evacuating rotor rotatably mounted in the housing for rotation in synchronism with the drum for entering and evacuating the pockets at a point adjacent the exit opening, the improvement comprising first and second elongated members disposed on opposite sides of the entry opening and extending generally parallel with and in spaced relation to the longitudinal edges of the drum, meaNs for mounting the first and second elongated members on the housing for movement toward and away from the drum to allow adjustment of the clearances between the first and second elongated members and the longitudinal edges of the drum, first and second end members disposed between the axial ends of the drum and the housing adjacent the ends of the entry opening and extending between the first and second elongated members, and means for mounting the first and second end members in spaced relation to the axial ends of the drum to allow adjustment of the clearances between the ends of the drum and the housing, the first and second elongated members and the first and second end members thereby defining with the drum an adjustable clearance boundary between the entry opening and the exit opening whereby materials of varying particle sizes may be accommodated.
 2. Apparatus as defined in claim 1 wherein each of the elongated members extends peripherally of the drum to an extent at least as great as the peripheral length of each of the pockets in the drum, and wherein each elongated member generally conforms throughout its peripheral extent to the circular path traced by the longitudinal edges of the drum.
 3. Apparatus as defined in claim 2 wherein each end member comprises a generally T-shaped member, the stem of the T being slidably received between the respective drum end and the housing and between the first and second elongated members, and wherein the means for mounting the first and second end members in spaced relation to the drum ends comprises notches formed in the legs of each end member for receiving the first and second elongated members to thereby support the end member on the first and second elongated members and spaced lugs carried by the stem portion of the end member and projecting therefrom a predetermined distance toward the housing, the terminal ends of the lugs being adapted to abut against the inner surface of the housing to position the end member in spaced relation to the axial end of the drum.
 4. Apparatus in accordance with claim 1 wherein the improvement further comprises self-tightening wire-blade means for the evacuating rotor, the wire-blade means including at least one length of wire extending axially and transversely of the drum pockets between a first axially-fixed sleeve carried by the rotor shaft and an axially movable sleeve carried by the rotor shaft, a compression spring disposed between the axially movable sleeve and a second axially fixed sleeve carried by the rotor shaft resiliently urging the axially movable sleeve in a direction away from the first axially-fixed sleeve to thereby maintain the length of wire in a tightened condition.
 5. Apparatus as defined in claim 4 wherein the wire-blade means further comprises a pair of guides mounted in opposed relation on the axially movable sleeve and wherein the length of wire extends over the pair of guides and is secured at both ends to the first axially-fixed sleeve.
 6. Apparatus as defined in claim 1 wherein the improvement further comprises force-feeding means communicating with the inlet hopper to provide a positive feed of material through the entry opening. 